No health check on external CDN [#2083259]

Hi,

The module does not seem to check whether an external CDN is alive, mapped resources return 404 rather than a fallback to using origin located resources.

Whether or not an external CDN is alive, the Stats continue to show that resources are being served from the CDN

Any help and your time appreciated,
Cheers

Comments

Comment #1

OriginalSauce CreditAttribution: OriginalSauce commented 14 September 2013 at 11:45

Priority:

Normal

» Major

Updated priority to major, as this breaks the site.

Comment #2

OriginalSauce CreditAttribution: OriginalSauce commented 14 September 2013 at 11:50

If this functionality is not available without a patch, I would've thought in theory it is possible to use cdn_pick_server to check whether the external cdn is running, and if not either return the origin address, or indeed a fake/subdomain cdn?

Will test...

Comment #3

Wim Leers

Ghent 🇧🇪🇪🇺

CreditAttribution: Wim Leers commented 18 September 2013 at 15:51

Category:	bug	» support
Priority:	Major	» Normal
Status:	Active	» Postponed (maintainer needs more info)

Are you using an Origin Pull CDN?

Comment #4

OriginalSauce CreditAttribution: OriginalSauce commented 19 September 2013 at 17:14

Hi,

Yes, it is an external Origin Pull CDN.

As mentioned in my previous post, looking at the cdn pick server option, it is possible to code something to either ping/curl etc, to see if the CDN(s) is live. The downside, doing an extra check for every file would in practice, be way to expensive.

I suspect this hasn't been considered before, because it's popular to use the module with fake/subdomain, and the rare occasion for downtime on the larger CDN networks.

Still if this isn't something that is considered a bug, could you point me to the best place in the module code where I might add something myself?

Thanks Wim

Comment #5

Wim Leers

Ghent 🇧🇪🇪🇺

CreditAttribution: Wim Leers as a volunteer commented 23 May 2015 at 18:14

Issue summary:	View changes
Status:	Postponed (maintainer needs more info)	» Fixed

Pinging the external CDN every request, and potentially multiple domains, that is going to be very bad for performance. I'd advise against it. But yes, it is possible.